Analisis Faktor-Faktor yang Mempengaruhi Sungai Ular di Kabupaten Deli Serdang

Abstract

In face to inbalance between the continously reduced supply of water and the increased demand of water, the water resources should be treated by considering social, environmental, and economical functions harmonically. The reduced supply of water also involved some rivers across the Riverflow throughout North Sumatra. The demand of capability to support the life system of society in using the water resources is so significant either downstream or upstream. The trend in reduced debit of the river water can be influenced by some factors such as irrigation (agriculture), industry, domestic and C-piled mine in the Riverflow, especially at the Ular River of Deli Serdang Regency as the object of research. The present research intends to know whether the supply of water of the Ular River as a natural resources can support any agricultural, industrial, domestic and C-piled mine and the factors influencing on the Ular River of Deli Serdang Regency. The equilibrium between the requirement and the availability of water should be maintained by making an integrated planning and treatment. The existence of the Ular River is now heavily depending on the activity of the community in the periphery. In general, the water debit of the Ular River in 1989 reached 66 m3/sec, and reduced to be 44 m3/sec. It reduced again in 2001 and 2004 to be 40m3/sec. The reduction of the water debit resulted in destruction to paddy production due to dryness of some regions around the River. The research location involved the Ular River of Deli Serdang Regency for the reason that there was approximately 18.500 hectares of wetland of the community along with the free intake distributing water for agriculture, domestic, office, industry, and dig-C mine. The Ular River was located in distance of approx 30 Kms away from Medan Municipality. The variables of the present research included land area, water debit of the Ular River, dig-C mine, activity of the local community, agriculture, industry in the periphery of the Ular River of Deli Serdang Regency. The data was analyzed using a descriptive approach by means of frequency tabulation, Rank Spearman statistic analysis and t-test. The findings showed that the potential Ular River still can support agriculture activity such as supply of water for irrigation, economic practitioners such as agricultural products, industry such as collection of water as raw materials for District Drinking Water Company for drinking water, dig-C mine such as sand, gravel, coral, and jade. The influencing factors on the potential Ular River especially of the water debit included allocation of water for agriculture (irrigation) and dig-C mine. It was indicated by the statistic analysis and found that t-test count > t-table. Whereas the allocation of water for industry, community, and urban activity showed that there was no domestic effect as indicated by the t count

Dalam menghadapi ketidakseimbangan antara ketersediaan air yang cenderung menurun dan kebutuhan air yang semakin meningkat, maka sumberdaya air wajib dikelola dengan memperhatikan fungsi sosial, lingkungan hidup dan ekonomi secara selaras. Ketersediaan sumberdaya air yang cenderung menurun tersebut juga dialami beberapa sungai sepanjang Daerah Aliran Sungai di Sumatera Utara. Tuntutan kemampuannya dalam menunjang sistem kehidupan masyarakat atas memanfaatkan sumberdaya air demikian besarnya baik bagian hulu maupun hilir. Kecenderungan menurunnya potensi (debit) air sungai di atas dapat dipengaruhi oleh beberapa faktor anrtara lain irigasi (pertanian), industri, domestik dan penambangan bahan galian C pada Daerah Aliran Sungai tersebut, khususnya Sungai Ular di Kabupaten Deli Serdang sebagai obyek penelitian. Penelitian ini bertujuan untuk mengetahui apakah ketersediaan air Sungai Ular sebagai sumberdaya alam dapat mendukung kegiatan pertanian, industri, domestik dan penambahan bahan galian C, serta faktor-faktor yang mempengaruhi Sungai Ular di Kabupaten Deli Serdang. Lokasi penelitian yang dilakukan ini adalah Sungai Ular di Kabupaten Deli Serdang dengan alasan di sekitar Sungai Ular terdapat sekitar 18.500 hektar persawahan masyarakat serta dilengkapi pintu masuk air (free intake) yang mendistribusikan air untuk kepentingan air pertanian, domestik, perkantoran dan industri serta penambangan galian C. Sungai Ular berjarak ? 30 km dari kota Medan. Variabel penelitian adalah luas lahan, debit air Sungai Ular, penambangan galian C, aktivitas masyarakat, pertanian, industri di sekitar Sungai Ular Kabupaten Deli Serdang; Analisa data yang digunakan adalah analisis deskriptif dengan bantuan tabulasi frekwensi, serta analisis statistik Rank Spearmen serta pengujian uji t. Hasil penelitian, potensi Sungai Ular masih mampu untuk mendukung kegiatan pertanian seperti ketersediaan air untuk irigasi, pelaku ekonomi seperti hasil pertanian, industri seperti pengambilan air bahan baku Perusahan Daerah Air Minum untuk air minum, penambangan bahan galian C berupa pasir, kerikil, koral dan batu mangga. Faktor-faktor yang mempengaruhi potensi Sungai Ular khususnya debit air adalah penggunaan air untuk pertanian (irigasi) serta penambangan bahan galian C. Hal ini dtunjukkan dari hasil analisis statistik serta dibuktikan oleh pengujian, uji t hitung > dari tabel. Sedangkan penggunaan air untuk kepentingan industri, penggunaan air untuk masyarakat dan untuk kegiatan perkotaan adalah tidak berpengaruh/ domestik, hal ini ditunjukkan dari besarnya harga t hitung < tabel.